Osteoporotic fracture is a complex trait due in large part to an age-related reduction in bone strength. Bone mineral density, bone structure, bone quality and bone structure are the main components of bone strength. All four components have phenotypes that are highly heritable. Successful localization and identification of genes underlying the components of bone strength, and in turn osteoporosis, depends on accurate phenotypic measurement and optimum genetic analyses. Our group at Indiana University has extensive experience in the management and analysis of large data sets for the detections of susceptibility genes for complex disease. During the last five years, we have successfully identified several chromosomal regions that contribute to the phenotypic variability observed in peak bone mineral density among women. During the next five years, the specific aims of Core C: Genetic Analysis and Bioinformatics Core will be: 1) to modify and adapt the study designs of the three projects so as to exploit novel methodological advances in genetic advances; 2) to perform linkage analyses in the three projects to identify genes contributing to bone mass; and 3) to develop a bioinformatics resource to assist in the identification of the genes contributing to bone mass.